You should have told your wife about the no dishwasher policy.
However...
My in-laws come over and insist on cleaning up after a meal. Like, they kinda give a passive aggressive attitude about it. So I usually take the bottle of brandy and chat it up, with my father-n-law. Well, for days after they leave I'm wondering where stuff is. If they (my mother and sister-n-laws) don't know where something goes, they just make their own place for it in my shelves and cupboards. I've discussed this with my wife because sometimes their ideas of how my kitchen should be arranged gets a little ridiculous, but my wife refuses to say anything. I can't say I blame her, it's her family and they're helping out. But if you insist on helping perhaps asking "where does this go", before placing the bisquick in with my china, or asking "Is this dishwasher safe..." would be better than just assuming. I think they call that being courteous and respectful.